Staple and method of and apparatus for applying it



Nov. 23, 1965 A. KLAUS 3,218,700

STAPLE AND METHOD OF AND APPARATUS FOR APPLYING IT Filed Jan. 20, 1964 Aa SI 2 United States Patent Office Patented Nov. 23, 1965 3,218,760STAPLE AND BETH-D OF AND APPARATUS FGR APILYEJG HT Arthur Klaus,Frankfurt am Main, Germany, assignor to Elastic Aktiengesellschaftvorrn. M. Vogei A.G., Frankfurt am Main, Germany Filed Jan. 20, 1964,Ser. No. 338,771 Claims priority, application Germany, Jan. 19, 1963, E24,206 13 Claims. (Cl. 29-4321) The present invention relates to staplesand to methods of and apparatus for stapling, and is concerned moreparticularly, but not exclusively, with the manufacture and closure ofcardboard boxes.

General objects of the invention include providing improvements forstaple constructions and for associated methods and apparatus, whilemore specific objects relate to the provision of improved structures andtechniques which avoid the formation of enlarged holes and slots in thematerials which are to be stapled so that a firm connection by thestaples is assured.

According to one aspect of the present invention there is provided amethod of stapling employing a staple having two side limbsinterconnected by a web which is folded into an intermediate shortenedform, said method comprising the steps of initially guiding a portion ofeach of said side limbs of said staple into a workpiece, subsequently ina direction normal to the surface of the workpiece applying pressure tosaid web to cause said web to assume its more fully extended orelongated form, said Web in turn thereby exerting a pressure on saidside limbs and urging the ends of said side limbs towards said web, andfinally continuing to exert a pressure in a direction normal to thesurface of the workpiece on said staple at the inner ends of said limbsto drive substantially all of said side limbs into said workpiece.

According to another aspect of the present invention, there is provideda preformed staple having a web, two side limbs interconnected by saidweb, said web having a folded central portion and two connectingportions disposed one at each end of said web, said central portionbeing so folded as to extend in the same direction as said side limbs,said connecting portions lying substantially parallel to the directionof driving movement of said staple during a stapling operation, saidconnecting portions and said central portion, when the latter is in itselongated form, having an aggregate length which is substantially equalto the length of the crown of said staple when the latter is driven intoa workpiece.

Furthermore, in accordance with the present invention, there is provideda stapling apparatus including a body portion defining an ejectionchannel adapted to receive a staple and having a width substantiallycorresponding to the length of the crown of said staple, when the latteris driven into a workpiece, two driving means mounted in said channeland displaceable relative to each other and to said channel, means foroperatively connecting said driving means to a pressure source, said twodriving means comprising an inner driving member and an outer drivingmember coupled together for carrying out sequential movements in astaple driving operation, the inner driving member having a widthsubstantially corresponding to the projection of said central foldedportion of the web of said staple, and being mounted and resilientlyguided in said outer driving member which defines a recess for receivingsaid inner driving member.

It is to be understood that by the term elongated form of the web, orany portion thereof, is meant the length of the web, or of said portion,after it has been straightened by the stapling operation and is embeddedin the workpiece. By the term shortened form of the web or any portionthereof is meant the length of the web or of said portion when thestaple is in its preformed state and prior to the stapling operation.

For a better understanding of the invention and to show how the same maybe carried into etfect, reference will now be had, by way of example, tothe embodiment illustrated in the accompanying drawings in which:

FIGURE 1a is a side elevation of a staple formed in accordance with oneembodiment of the invention;

FIGURE 1b is an end elevation of the staple of FIG. 1a;

FIGURE 2 is a schematic front elevation of an injection channel in astapling apparatus constructed in accordance with the invention withoutthe cover plate thereof;

FIGURE 3 is a vertical section through the mid-portion of FIG. 2,including the cover plate; and

FIGURES 4 to 6 are views corresponding to FIGURE 2 and showing thecomponents of the stapling apparatus in different positions sequentiallyfollowing the position shown in FIG. 2 including the diiferent positionsand shapes imparted to the staple.

The staple illustrated in FIGS. 1a and 111, comprises a Web generallyindicated at 1, which is shortened relative to the form it assumes uponinsertion in a workpiece, the insertion being effected by two measures,as will be shown. A central portion 1a of the web 1 is, by known bendingtechniques, reduced to a width a. At the ends of the central portion 1aare bent-up connecting portions 1b which are parallel to each other. Theconnecting portions lb are provided with side limbs 2 bent overdownwardly at an acute angle at corner regions 1c. In this condition,the shape of the staple is such that spacing b between the limb ends isgreater than the shortened length a of the central portion 1a, theelongated length of the central portion 1a and the length of theconnecting portions 1b corresponding to the length of the crown of thestaple when fixed in position on the workpiece (see FIG. 6).

The method according to the invention may be carried out by means of astapling machine such as is illustrated in FIGS. 2 to 6. These figuresshow (in diagrammic form) the steps necessary for carrying out themethod, without dealing with constructional details of the apparatus.

FIG. 2 shows an ejection channel 3 which is laterally defined by twoshoulders 4- and covered by a cover plate 5 (FIG. 3). The staples arepushed one after the other by a known feeder device into the ejectionchannel 3. The width of the ejection channel 3 corresponds to theelongated length of the web parts la and 1b.

Displaceably guided in the ejection channel 3 is a generally U-shapeddriving member 6 which is connected with a driving block 7 (FIG. 3).Disposed in a transverse recess 8 in the block 7 is a driving rod 9 bymeans of which, with known driving means, the driving member 6 can bedisplaced for the purpose of ejecting staples 1.

Displaceably guided between limbs 1t of the driving member 6, and in theplane thereof, is a second driving member 11. Abutments 12 locatedbetween the two driving members e and 11 define the relativedisplacement permissible between said driving members. In thisconnection, the inner driving member 11 is influenced, through theintermediary of a spring 13, by the driving member 6, the tension or"the spring being such that the inner driving member 11 is positioned inthe direction of movement in advance of the outer driving member 6.

With the lowering of the two driving members 6 and 11, brought about bydepression of the rod 9, the apex formed by the bending of the centralportion 1a meets the workpiece into which the staple is to be insertedand is halted thereby. Meanwhile the free ends of the side limbs 2 haveentered the workpiece (see FIG. 4) and, as the limbs of the drivingmember 6 continue downward, more of the limbsZ are forced into theworkpiece. Simultaneously, the spring 13 is tensioned and exerts asupplementary pressure on the inner driving member 11 so that the latteris further lowered for the purpose of stretching the central portion 1aof the web 1. This forces the acute angle corner regions 10 of theconnecting portions 1b to be displaced outwardly away from the drivingmember 11, and the staple and apparatus assume the position shown inFIG. 5, the corner regions 10 being guided in their downward path bycontact with the lateral shoulders 4 of the ejection channel 3.

Since, in this position of the parts, the inner drive member 11 hasalready reached its lowermost position, further downward movement of thedriving rod 9 will only move downwardly the outer driving member 6. Dueto this sequential movement, the free ends of the limbs are driven theentire lengths of the side limbs into the workpiece and the web isbrought to its full elongated length and the limbs 2 are folded-in underthe web 1 as shown in FIG. 6.

To explore more thoroughly the relationship of the ditferent elements ofthe staple as illustrated in FIG. In, reference is now made to the factthat the central portion 1a of the web 1 includes a centrally locatedfulcrum F and two sections S1 and S2 extending away from the fulcrum andangularly related to each other, the side limbs 2 being adapted forconnection to said sections, this connection being effected throughconnecting portions 11). It will be further noted that the connectingportions 1b are hingeably connected to the sections S1 and S2 and to theside limbs 2 for connecting the latter to the sections S1 and S2.

It will be further understood that the sections S1 and S2 with thefulcrum F define a direction D of driving movement for the staple, theconnecting portions 1b being parallel to each other and to the saiddirection. It will be moreover understood that the side limbs 2 curvefrom the connecting portions in a direction which is generally alignedwith the direction D.

As regards the relative length of the sections S1 and S2, these shouldpreferably be of equal length such as to define an isosceles triangle,the base of which is indicated at B and the apex of which corresponds tothe fulcrum F.

It will be moreover noted that the web and connecting portions and sidelimbs constitute the parts of a single continuous piece of suitablematerial such as metallic wire.

Attention is again directed to the fact that the side limbs are providedwith pointed free-end portions E1 and E2, which are spaced apart at adistance b which exceeds the spacing a between the connecting portions1b.

It will also be noted that the side limbs 2 are of a height H in thedirection D which is less than the total length of the associatedconnecting portion 1]) and section S1 or S2, respectively, of the web.This is, for example, evident in FIG. 6, wherein it is seen that whenthe sections of the web and connecting portions are flattened, the freeends of the side limbs approach one another but do not overlap. In thisconnection it should be noted that the somewhat sketchy drawing is notthroughout true to scale and that in particular the lengths and shapesof the different parts of the staple do not match exactly in differentfigures and do not exactly correspond to the definitions specified inthis description which, of course, is controlling.

In addition it will be noted that the height H of the side limbs exceedsthe combined height h of the isosceles triangle and connecting portions.This enables the free ends of the staple to enter into a workpiecebefore the fulcrum F encounters the workpiece or an anvil such that theweb may be deformed to flattened condition.

As regards the driving member 10 (see FIG. 2), attention is directed tothe fact that this member is provided with inclined free extremities Iintended to engage the cornet regions 1c, such that appropriatedisplacement forces may be imparted to the connecting portions 1b.

There will now be obvious to those skilled in the art many modificationsand variations of the structures and techniques set forth above. Thesemodifications and variations will not depart from the scope of theinvention it defined by the following claims.

What is claimed is:

1. A method of stapling employing a staple having two side limbs havingfree outer ends and being interconnected by a web, wherein said web hasa folded central portion and one connecting portion provided betweeneach end of said central portion and a respective side limb, saidconnecting portions lying substantially parallel to the direction ofdriving movement of said staple during a stapling operation, said methodcomprising the step of firstly applying pressure to said central portionto flatten said folded central portion into elongated form whiledisplacing said connecting portions outwardly at an angular positionrelative to said direction of driving movement and guiding the free endsof said side limbs into the workpiece, and of then applying furtherpressure to said displaced connecting portions to cause said connectingportions to bend outwardly until it lies substantially in a common planewith said flattened central portion.

2. A preformed staple comprising a web, two curved side limbsinterconnected at one of their ends by said web, said limbs having outerfree ends adapted to penetrate into a workpiece, said web including afolded central portion and two connecting portions disposed one at eachend of said central portion of said web, said central portion having endsections converging toward each other in the same direction as said sidelimbs, said connecting portions including an obtuse angle with therespective end section of said central web portion, said staple having adirection of driving movement for a stapling operation which is parallelto the general direction of said connecting portions, said connectingportions and said central portion in elongated form having an aggregatelength which constitutes the length of the crown of said staple when thelatter is driven into a workpiece.

3. A stapling apparatus for inserting a staple having two side limbsprovided with :free outer ends and having their other endsinterconnected by a web, the latter including a folded central portionand two connecting portions at the ends of said central portion, saidapparatus includ ing a body portion defining an ejection channel adaptedto receive a staple and having a width substantially corresponding tothe length of the crown of said staple when the latter is driven into aworkpiece, two driving means mounted in said channel and displaceablerelative to each other and to said channel in a longitudinal directionof the latter, means for operatively connecting said driving means to apressure source, said two driving means comprising an inner drivingmember and an outer driving member, coupled together for carrying outsequential movement in a staple driving operation, the inner drivingmember having a width substantially corresponding to the length of saidcentral folded portion of the web of said staple and being resilientlymounted in said outer driving member which defines a recess forreceiving said inner driving member.

4. An apparatus according to claim 3 wherein said outer driving memberhas an inclined surface which during the stapling operation bends theends of the connecting portions remote from said central portion of thestaple outwardly so that said connecting portions lie substantially onthe axis of said central portion.

5. A staple comprising a central web including a centrally locatedfulcrum and two sections extending away from the fulcrum and angallarlyrelated to each other, side limbs having free outer ends adapted forentering a workpiece, and connecting portions connected to said sectionsand said side limbs for connecting the other ends of the latter to saidsections, said sections and fulcrum defining a direction of drivingmovement for the staple, said connecting portions being parallel to eachother and to said direction, said side limbs curving laterally away:from said connecting portions and being generally aligned with saiddirection.

6. A staple as claimed in claim 5, wherein said sections are of equallength and define an isosceles triangle having an apex corresponding tosaid fulcrum.

7. A staple as claimed in claim 5, wherein said side limbs includepointed free end portions spaced apart at a distance exceeding thespacing between said connecting portions.

8. A staple as claimed in claim 5, wherein the side limbs are of aheight along said direction, which is less than the total length of thesaid associated connecting portions and sections of said web.

9. Stapling apparatus adapted for employing a staple comprising acentral web including a centrally located fulcrum and two sectionsextending away from the fulcrum and angularly related to each other,side limbs having free outer ends adapted for entering a workpiece, andconnecting portions connected to said sections and side limbs torconnecting the latter to said sections, said sections and fulcrumdefining a direction of driving movement for the staple, said connectingportions being parallel to each other and to said direction, said sidelimbs curving laterally away from said connnecting portions and beinggenerally aligned wit-h said direction; said apparatus comprising firstmeans defining an ejection channel through which said staple can pass insaid direction of driving movement, second means to apply a flatteningpressure to said central web by displacing said sections about saidfulcrum whereby said connecting portions are displaced to an angularposition relative to said direction, and third means operative, with thecentral web flattened,

to apply a flattening force to said displaced connected portions tobring the latter into coplanar relationship with said web.

10. Apparatus as claimed in claim 9, wherein the second and third meansare interengaged in relatively displaceable manner, comprising springmeans urging the second and third means to a relative position in theejection channel whereby the second means functions to apply itsflattening pressure before the third means applies its flattening force.

11. Apparatus as claimed in claim 9, wherein the third means is aU-shaped member including legs between which said second means isslidably accommodated.

12. Apparatus as claimed in claim 9, wherein the second means is aU-shaped member including legs between which said third means isslidably received, and wherein said legs include inclined free endportions for engaging said connecting portions of a staple.

13. Apparatus as claimed in claim 9, wherein the second and third meansinclude means for locking the same together while permitting limitedmovement therebetween.

References Cited by the Examiner UNITED STATES PATENTS 1,868,100 7/ 1932Goodstein 2943 2.1 1,910,688 5/1933 Goodstein 49 1,945,377 1/ 1934Posnack 227139 X 2,008,086 7/1935 Sorenson 156 XR 2,153,874 4/ 1939Posnack 29-4321 3,07 7,812 2/ 1963 Dietrich 1-74 XR WHITMORE A. WILTZ,Primary Examiner.

GRANVILLE Y. CUSTER, Jr., Examiner.

1. A METHOD OF STAPLING EMPLOYING A STAPLE HAVING TWO SIDE LIMBS HAVINGFREE OUTER ENDS AND BEING INTERCONNECTED BY A WEB, WHEREIN SAID WEB HASA FOLDED CENTRAL PORTION AND ONE CONNECTING PORTION PROVIDED BETWEENEACH END OF SAID CENTRAL PORTION AND A RESPECTIVE SIDE LIMB, SAIDCONNECTING PORTIONS LYING SUSBTANTIALLY PARALLEL TO THE DIRECTION OFDRIVING MOVEMENT OF SAID STAPLE DURING A STAPLING OPERATION, SAID METHODCOMPRISING THE STEP OF FIRSTLY APPLYING PRESSURE TO SAID CENTRAL PORTIONTO FLATTEN SAID FOLDED CENTRAL PORTION INTO ELONGATED FORM WHILEDISPLACING SAID CONNECTING PORTIONS OUTWARDLY AT AN ANGULAR POSITIONRELATIVE TO SAID DIRECTION OF DRIVING MOVEMENT AND GUIDING THE FREE ENDSOF SAID SIDE LIMBS INTO THE WORKPIECE, AND OF THEN APPLYING FURTHERPRESSURE TO SAID DISPLACED CONNECTING PORTIONS TO CAUSE SAID CONNECTINGPORTIONS TO BEND OUTWARDLY UNTIL IT LIES SUBSTANTIALLY IN A COMMON PLANEWITH SAID FLATTENED CENTRAL PORTION.
 2. A PREFORMED STAPLE COMPRISING AWEB, TWO CURVED SIDE LIMBS INTERCONNECTED AT ONE OF THEIR ENDS BY SAIDWEB, SAID LIMBS HAVING OUTER FREE ENDS ADAPTED TO PENETRATE INTO AWORKPIECE, SAID WEB INCLUDING A FOLDED CENTRAL PORTION AND TWOCONNECTING PORTIONS DISPOSED ONE AT EACH END OF SAID CENTRAL PORTION OFSAID WEB, SAID CENTRAL PORTION HAVING END SECTIONS CONVERGING TOWARDEACH OTHER IN THE SAME DIRECTION AS SAID SIDE LIMBS, SAID CONNECTINGPORTIONS INCLUDING AN OBTUSE ANGLE WITH THE RESPECTIVE END SECTION OFSAID CENTRAL WEB PORTION, SAID STAPLE HAVING A DIRECTION OF DRIVINGMOVEMENT FOR A STAPLING OPERATION WHICH IS PARALLEL TO THE GENERALDIRECTION OF SAID CONNECTING PORTIONS, SAID CONNECTING PORTIONS AND SAIDCENTRAL PORTION IN ELONGATED FORM HAVING AN AGGREGATE LENGTH WHICHCONSTITUTES THE LENGTH OF THE CROWN OF SAID STAPLE WHEN THE LATTER ISDRIVEN INTO A WORKPIECE.
 3. A STAPLING APPARATUS FOR INSERTING A STAPLEHAVING TWO SIDE LIMBS PROVIDED WITH FREE OUTER ENDS AND HAVING THEIROTHER ENDS INTERCONNECTED BY A WEB, THE LATTER INCLUDING A FOLDEDCENTRAL PORTION AND TWO CONNECTING PORTIONS AT THE ENDS OF SAID CENTRALPORTION, SAID APPARATUS INCLUDING A BODY PORTION DEFINING AN EJECTIONCHANNEL ADAPTED TO RECEIVE A STAPLE AND HAVING A WIDTH SUBSTANTIALLYCORRESPONDING TO THE LENGTH OF THE CROWN OF SAID STAPLE WHEN THE LATTERIS DRIVEN INTO A WORKPIECE, TWO DRIVING MEANS MOUNTED IN SAID CHANNELAND DISPLACEABLE RELATIVE TO EACH OTHER AND TO SAID CHANNEL IN ALONGITUDINAL DIRECTION OF THE LATTER, MEANS FOR OPERATIVELY CONNECTINGSAID DRIVING MEANS TO A PRESSURE SOURCE, SAID TWO DRIVING MEANSCOMPRISING AN INNER DRIVING MEMBER AND AN OUTER DRIVING MEMBER, COUPLEDTOGETHER FOR CARRYING OUT SEQUENTIAL MOVEMENT IN A STAPLE DRIVINGOPERATION, THE INNER DRIVING MEMBER HAVING A WIDTH SUBSTANTIALLYCORRESPONDING TO THE LENGTH OF SAID CENTRAL FOLDED PORTION OF THE WEB OFSAID STAPLE AND BEING RESILIENTLY MOUNTED IN SAID OUTER DRIVING MEMBERWHICH DEFINES A RECESS FOR RECEIVING SAID INNER DRIVING MEMBER.